Spark-plug



G. A'. BELLr SPARK PLUG. APPLICATION FILED MAY 26. 1917.

133,552,775, PatentedSept. 14,1920i4 d j/I'y I T 1.527 'l ,I .5g fB I21.. Z).- "sI t? Jl? I Ik W '1T ,KM J

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entre? rares GEORG-E A. BELL, OF SILVER CREEK, NEW' YORK, ASSIGNOR OFONEHALE TQ LE ROS C. HAMMOND, OF SILVER CREEKLNEW YORK. l

l 'SPARK-PLUG.

Application filed May 26,

Amore particularly to what may he termed a self-cleaning spark plug.A

- @ne of the objects of my invention is the production of aself-cleaning -spark plug wherein provision is made for automaticallycleaning lthe electrodes oi the spark plug and retaining the spacebetween them unobstructed uniler ell working conditions.

Another obj ect oii'iny invention is the provision of a self-cleaningspark plug' wherein the electrodes are disposed in alinement and whereinan automatic cleaning device is arranged to move lengthwise on saidelectrodes, vsaid cleaning device heilig constructedand arranged toassure reciprocable movement thereof with each cycle ol the enginepiston cooperating with the spark plug.

Another object is the provision of a selfcleaning device movablelengthwise along alinedelectrodes andl adapted to be limited in itsoutward moveinent by the porcelain or other insulating core of the sparkplug,

-sa-id cleaning device being provided with means to assure an inwardmovement of the same with or immediately following each explosion' ofthe gases within the cylinder to which the spark plug is attached.

A further object is the provision of a lspark plug having novel meansfor automatically cleaning the electrodes thereof and which means aresimple,v inexpensive` and durable, said means being further conf'struc'ted of a material which .will assure a the spark plug isattached.

'Vl/'ith these and other objects in view, the invention consists in aspark plug having al pair of electrodes and a movable cleaning deviceconstructed of conducting material which will assure a spark of greatermagnitude and intensity.

The invention also consists in a spari'- plu having alined electrodesand a reeiprdI i. cleaning device movabfie alongsaid vinto a cylinder ofan engine. cured within this outer or ground casing B, `is a porcelainor other insulating 'core C through which the power electrode D `i`s'1917. Serial No. 171,140.

electrodes-and constructed'to assure' an in Specification of LettersPatent. Patented Sept., l'l, i920.

ward movement thereof with or immedii ately following each explosionwithin the' cylinder to which the spark is attached. ,i

The invention further consists in aspark plug having a pair of alincdelectrodes and a metallic element surrounding saidf electrodes andmovable lengthwise thereon, element having` an explosion chamber there-.in whereby thc exploding gases-are caused to force 'the elementinwardly f along` Ithe electrodes withI or immediatelyv following eachexplosion of the gases within the cylinlder to which Vthe plug isattached. A f ,A It ,further consists in thenovell features of'construction'andin thc arrangement 'id combination of parts to behereinafter ijlescribed and more particularly pointed hout in thesubjoined claims. l'

In the drawings,- .Y Figure l isl a side View of a spark plug embodyingwhat I now` coi'isider thev plie.'-

fei'red form of my invention. v ,.1 Fig. 2 is a sectional elevation ofthe lower or inner portion of the spark plugl on lany enlarged scale,the cleaning device being at its innermost point of movement.

device at its outermost point oi inovementl Fig. t is a plan view of thecleaning'device.' i' i. i `Fig. 5 is an inverted view of the same.

Irg. 3 is a similar view with the cleaning In the preferred embodimentolimyinl,

vention shown in thc drawings, but which may be greatly modified withoutdeparting from the spirit of my invention, A repre-,x

' sents the spark plug considered asa whole'` This spark plug is ot thetype having outer or ground casing B constructed suitable currentconducting material, as is common, and having an vexternal thread bwhich permits .of the`plug beine` threaded Silitably sepassed. The innerend of this plug is shown as terminating short ot the inner end or" theouter or ground casing with the power elec` trode I) extending inwardlyVtherefrom" aV short distance. The outer end of said elec! ti'ode'l) isprovided with a binding nut between which and a washer E surroundingsaid electrode, a circuit wireF is clamped.

G designates the ground-electrodewhich" is -fastened into the outer orground casing B, -as at y, it being directed inwardly from its point ofattachment to said casing and thence'radially,A as at H, to a pointcoiiicident=with the axis of the power electrode D, thencel outwardly inalinenient with said power electrode, as at h, forming a substantiallyU-shaped electrode with its spark terminal terminating a short distancefrom the inner end of said power electrode to Jrovide theusual sparkingspace or gap I between the' two electrodes.

1t is of course to be understood that the spark plug may be variouslyformed and that the herein illust ation thereof is merely representativeof the general type of spark plugs to which tliisinvention isparticularly adapted.y The arrangement of the electrodes shown is,however, highly desirable since it enables the use of'my improvedelectrode cleaning vdevice in its simplest form. The principle of myinvention, however, could readily be applied in spark plugs havingelectrodes otherwise arranged.

It is also to be understood that the current is carried through theouter vor ground. easing of the spark plugin the usual manner, thecurrent being passed through the engine casing into which the spark plugis threaded, a ground wire being fastened to the engine easing for thispurpose, as is In the preferred form of my invention l employ acomparatively small cast-iron cleaner member'J, which is preferablycylindrical and of a depth -or height somewhat less than the length'ofthat portion of the power electrode extending from the porcelain yorother insulating core C, as clearly shown in Fig. 3, wherein the cleaneris inits outermost position in contact with the inner end of said coreThe depth or height of. this cleaner is preferably somewhat greater thanthe length yof the short leg /i or terminal-of the U-shaped groundelectrode, as clearly shown in Fig. 2. This cleaner has an axial openingj, counterbored at its outer end, as at K, the counterbore serving as achamber for the reception o'r compressed gases when the cleaner is inits outermost position against the inner end oi the core C, said coreserv-ing as one of the walls of the' chamber, as clearly shown in rig.a.

Extending laterally from said couiiterboi'e or chamber to the outerperiphery of the cleaner are one 'or more passages or ducts I.: whichserve as inlet passages for the chamber formed by the counterbore andcore (ff. This cleaner, as stated, is preferably formed of cast-ironandwhen in its innermost position, shown in F ig. 2, has'both electrodesD and G terminating within said counterbore,' consequently when in thisposition and the current is passed through the spark plug the flaringwalls of the counterbore serveas' a sparking surface as well as theextreme Vterininal of the ground electrode, thus assuring a spark ofgreater magnitude and intensity lthan under the usual conditions of usein a spark plug of this type. This condition of operation will beencountered when starting a multi-cylinder engine'on a battery; the

cleaners of the spark plugs of one or more i cylinders being forcedoutwardly under thel compression created by the outward movement of thepiston or pistons, While at other spark-plugs, sparks will be createdwhile the cleaners are at their innermost points of movement. l

When starting an engine with a magneto.

the spark is created only in that cylinder of the engine in which thegases are being i the counterbore K of the cleaner through .the

ducts or passages and when ignition of the gas takes' placewitliin thecylinder, the gas within said eounterbore or within the chamber of thecleaner formed by said counterbore and the core C is also ignited andthe cleaner forced inwardly. The explosion of the gas within the chamberof the cleaner takes place'immediately after the explosion in thecylinder so that there is no coun,- tei'acting force to retain thecleaner iii its outermost position. It is of course apparent that theducts 4or passages may be dispensedl with, since the rases would becrowded into the counterbore during the outward movement of the cleanerand trapped therein as the cleaner seats it-selfl against the inner endofthe core C; but I consider the use of such duitser passages highlydesirable since they assure a greater compression of the gases withinthe counterbore or chamber K.

It is ofcourse understood that the bore'j through the cleaner must be ofa slightly Vlarger diameter-than the electrodes D and G so that thecleaner may act easily in its movement on said electrodes, and duringthe operation of an engine to which the spark plug is attached thecleaner is moved outwardly'during each outward movement of thecoperating piston, and moves inwardly by gravity; and when there is oodcompression due to proper packing o the pist0nby.gravity assisted bysuction; but to assure proper and continual movements. of the cleaner,reliance is had on the explosion of the gases Within the counterbore, onthe particular cycle of the piston at which explosion of the gaseswithinthe cylinder takes place. Consequently during thegoperthe spark plug andoftentimes render the same inoperative.

In order that the cleaner, which owing to its bobbing movements may betermed a bobberf7 be retained properly upon the electrodes, andparticularly upon the terminal of the groundelectrode G without tippingthereon, I have provided a stop L which is in the form of a wire securedinto the outer or ground casing B in a manner similar to the groundelectrode G, the wire extending inwardly from the inner edge of saidcasing parallel with the alined electrodes and Gr and being thencedirected radiallyl in line with the radial portion H of the groundelectrode, the inner end terminating short of the ground electrode, asshown at l.. The bobber, so called, therefore rests upon the radialportion H of the ground electrode at one side of its'main axis, andagainst the stop L at the other`A sideithereof and is held with its borein alinement with the power electrode D 'so that free action is assuredat all times.

It is to be understood that this bobber or cleaning-device may be formedof material 'other than cast-iron, whether a conducting material or anon-conducting material, but I have found iii practice thatcast-iron'possesses high current-conducting qualities and thereforeinsures a fatter y spark than other irons, or alloys; and furthermore,it does not permit the accumulation of carbon thereon. It consequentlyremains clean and smooth and alsol keeps the electrodes 'in a cleancondition so that a very effective Spark is obtained under all workingconditions arid greater power and vmore mileage se-. cured per gallonconsumption of gasoleneY or other power agency used to operate theengine.

Since my invention as shown and described illustrates merely what I nowconsider the simplest form of adaptation, it is apparent that, withoutdeparting from the spirit of the invention or sacrificing any of theadvantages thereof, it may be modified for use in connection with sparkplugs of different construction 4than herein shown and described, andwhere in the claims I' refer to electrodes I do not intend to confinemyself to the useof wires or other slenderelongated members servingassuch, but wish to have it understood thatby suoli term I include allsurfaces spaced apart to fprovide' a gap which the electric current isto jump for creating a spark.-

Now therefore, what I claim is,-- l. A spark plug provided with a pairof ialined electrodes, ya cleaning device compris- -ng acomparativelysmall'body having a center bore and a counterbore at oneend of said center bore, said center lbore being adapted to receive saidelectrodes and permit lengthwise movement of said body on saidelectrodes, said body having a passage extending therethrough from theperiphery thereof to said counterbore.

2. In a Vspark plug, a cleaning device 'adapted for-movementin contactwith the electrodes thereof and comprising a body portion having acenter bore and a counter- Vbore at one end of said center bore,'saidbody also having a passage leading from the exterior thereof to saidcounterbore.

3. A spark plug comprising an outer or ground casing, an insulating corewithin said casing anda pair'of electrodes, one of said electrodesprojecting from said insulating core; combined with a cleaning device inthe form of a solid body having a bore to receive one of saidelectrodes,said bore being flared at. 011e end to serve as a chamber and saidchamberopeniiig'toward said core.

In testimony whereof I aix my signal'fllI'e.

GEORGE A. BELL.

